Earth drilling devices, in particular horizontal drilling devices, are used to introduce earth drill holes into the soil by trenchless construction for supply and waste lines, for example, or to replace already installed old lines without a trench. To introduce the earth drill hole, generally a drill string having drill string sections is used, wherein the drill string sections are connectable to each other.
The use of a slide that can be moved back and forth in a frame for advancing and/or retracting a drill string is known from EP 0 886 034 B1, for example. The slide has a seat for a drill string section such that the drill string section can be moved in the seat in the direction of a feed axis to create the earth drill hole. The drive acting on the drill string section can act on the drill string section in the seat in a rotational and/or translatory manner.
When advancing a drill string, normally the seat is disconnected from the (drilled) drill string already introduced into the soil, and the slide is moved opposite the feed direction, and a new drill string section to which the already drilled drill string is to be connected, is inserted into the seat of the slide. The slide is moved in the feed direction, and the drill string section is connected to the already drilled drill string, and is introduced further into the soil with the already drilled drill string.
A disadvantage with this is that the compact design of the frame with the slide makes handling difficult when introducing and removing a drill string section from the seat of the slide, in particular when a frame and slide arranged therein are in a trench. Furthermore, the size of the frame and the path of movement of the slide within the frame dictate the maximum size of the drill string sections to be connected to each other, which imposes restrictions even though drill string sections are desired that are as long as possible.